Introducing QUIC and HTTP/3

QUIC [1] is a new transport protocol that provides similar service guarantees to TCP, and then some, operating over a UDP substrate. It has important advantages over TCP:

  • Streams: QUIC provides multiple reliable ordered byte streams, which has several advantages for user experience and loss response over the single stream in TCP. The stream concept was used in HTTP/2, but moving it into the transport further amplifies the benefits.
  • Latency: QUIC can complete the transport and TLS handshakes in a single round trip. Under some conditions, it can complete the application handshake (e.g. HTTP requests) in a single round-trip as well.
  • Privacy and Security: QUIC always uses TLS 1.3, the latest standard in application security, and hides much more data about the connection from prying eyes. Moreover, it is much more resistant than TCP to various attacks on the protocol, because almost all of its packets are authenticated.
  • Mobility: If put in the right sort of data center infrastructure, QUIC seamlessly adjusts to changes in IP address without losing connectivity. [2]
  • Extensibility: Innovation in TCP is frequently hobbled by middleboxes peering into packets and dropping anything that seems non-standard. QUIC’s encryption, authentication, and versioning should make it much easier to evolve the transport as the internet evolves.

Google started experimenting with early versions of QUIC in 2012, eventually deploying it on Chrome browsers, their mobile apps, and most of their server applications. Anyone using these tools together has been using QUIC for years! The Internet Engineering Task Force (IETF) has been working to standardize it since 2016, and we expect that work to complete in a series of Internet Requests for Comment (RFCs) standards documents in late 2020. 

The first application to take advantage of QUIC is HTTP. The HTTP/3 standard will publish at the same time as QUIC, and primarily revises HTTP/2 to move the stream multiplexing down into the transport. 

F5 has been tracking the development of the internet standard. In TMOS, we released clientside support for draft-24 of the standard. That is, BIG-IP can proxy your HTTP/1 and HTTP/2 servers so that they communicate with HTTP/3 clients. 

We rolled out support for draft-25 in and draft-27 in While earlier drafts are available in Chrome Canary and other experimental browser builds, draft-27 is expected to see wide deployment across the internet. While we won’t support all drafts indefinitely going forward, our policy will be to support two drafts in any given maintenance release. For example, supports both draft-24 and draft-25. 

If you’re delivering HTTP applications, I hope you take a look at the cutting edge and give HTTP/3 a try! You can learn more about deploying HTTP/3 on BIG-IP on our support page at K60235402: Overview of the BIG-IP HTTP/3 and QUIC profiles.

-----[1] Despite rumors to the contrary, QUIC is not an acronym.

[2] F5 doesn’t yet support QUIC mobility features. We're still in the midst of rolling out improvements.

Published Apr 02, 2020
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